How to prevent duplicate entry

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i have a user-form created using linked to an access database. i have a column header named "PV Numbers". i would like to know how i can prevent users from duplicating the PV Numbers.

What I have tried:

The code am currently using is "GBCPVRBindingSource.AddNew"

Posted 8-Feb-17 5:16am

Kobby Adom

Updated 8-Feb-17 5:41am

F-ES Sitecore

v2

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Peter Leow · Answer 1 · 2017-02-08T05:26:00

Solution 1

Every table in a database must have a primary key[^] and that is what you are looking for.
Learn more: SQL PRIMARY KEY Constraint[^]

Posted 8-Feb-17 5:26am

Peter Leow

Updated 8-Feb-17 5:28am

v2

Patrice T · Answer 2 · 2017-02-08T05:41:00

Solution 2

As Peter said, "Primary key" is the way.
You need to learn better SQL.
SQL Tutorial[^]
W3Schools Online Web Tutorials[^]

Posted 8-Feb-17 5:41am

Patrice T

Comments

Kobby Adom 8-Feb-17 11:56am

forgive me if i come across as naive cos as i said a m really, really new to VB. But my connection to the access database is not through SQL. Its a simple access connection. The whole code is
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
GBCPVRBindingSource.AddNew()
End Sub

Patrice T 8-Feb-17 12:13pm

Access is an SQL server and 'primary ley" is on server side setting for a columns of the table.

Kobby Adom 8-Feb-17 12:44pm

Thanks ppolymorphe. i have been able to get the PV Number to be the primary key through my VB Express Dataset page. I hope it will do the trick for me and prevent duplication of PV Numbers?